Stefan Irmer has gained renown as an outstanding interpreter of unknown and rarely performed works of the piano literature. In concert series, discussion concerts, radio features, and radio productions he has presented the piano music of Muzio Clementi and Gioacchino Rossini to the public. His recording of Clementi's most important sonata cycles on three CDs on the MDG label received the CHOC French recording prize. In other programs Irmer has turned to the music of Erik Satie, John Field, Giacomo Meyerbeer, and Gabriel Fauré and initiated projects with singers, actors, and plastic artists on the occasion of the anniversaries of the birth of Friedrich Nietzsche in 1994 and Heinrich Heine in 1997.
As a song accompanist, Irmer has appeared with numerous renowned singers and taught and accompanied at master classes and competitions. He has performed together for many years with the bass Kurt Moll, with whom he has presented song recitals in the Hamburg State Opera, Lausanne Opera, Cologne Philharmonic Hall, and Milan Scala.